Homozygous viable. Nonsense and splicing alleles identified by amplicon sequencing. The gk5263 mutation is G->A, flanking sequences TTTTTCGTATTTTCAATTTCCAATGTTTCA and CCTTCTTTGTGTCCTTGCCTTGGTCATGTG. The gk5264 mutation is G->A, flanking sequences ATCTTCTTACCTTTGCTCCTTTCGGAGCTT and ATCTTCCCAGCTGATTTCCCTGGCCATAGA.